Good day! When I was using my pc for hours, the monitor suddenly turned off after a short beep sound in the system unit so the monitor is off while the system unit is still running. I was forced to turn off the system using the avr. When I turned it on, the keyboard and mouse are not working even if they are properly connected. I was forced to improperly shut it down again. What can I do to address this problem because this happens everytime I work with my pc for a long period? Response are highly appreciated.